Sustainable Agriculture: A Way Out of Food Poverty

The most fundamental human right is the right to food (UN General Assembly, 2002). Proper nutritious food is the precondition for normal human development. Well-nourished children are more likely to succeed in learning and are less susceptible to diseases. But low-income, food-importing economies are facing increasing difficulties in accessing staple food items. Chronic food insecurity persists, especially in Sub-Saharan Africa. The recent economic crisis drove more than 100 million people into hunger in 2008 alone. Is sustainable agriculture a solution?Sustainable Agriculture: A Way Out of Food Poverty

Role of food availability in the bathymetric distribution of the starfish Marthasterias glacialis (Lamk.)on reefs of northern Portugal [Efecto de la disponibilidad alimenticia sobre la distribución batimétrica de la estrella de mar Marthasterias glacialis (Lamk.) en arrecifes del norte de Portugal]

We examined whether the abundance and size of the starfish Marthasterias glacialis (Lamk.) exhibit a depth-dependent partitioning on subtidal reefs. We tested the hypothesis that differences in food availability can result in habitat partitioning along a depth gradient. The abundance and size of M. glacialis was registered at 4 depth strata: 0-4 m, 4-8 m, 8-12 m, and \u3e12 m; we also recorded the number of food items that they were preying on. The abundance and size of M. glacialis decreased with depth. Mussels (Mytilus galloprivincialis) were the most preyed food item across all depth strata, followed by gastropods, sea urchins and barnacles; M. glacialis also consumed a significantly larger amount of mussels in feeding experiments compared with sea urchins and gastropods. The abundance of M. galloprivincialis beds decreased with depth. The clear link between the decrease in abundance and size of M. glacialis with depth and the decay of the most consumed prey (mussels) suggest that food availability may play an important role in the vertical distribution of this starfish, though wave-associated turbulence in the first few metres of the subtidal could also limit the abundance of M. glacialis

Efecto de la disponibilidad alimenticia sobre la distribución batimétrica de la estrella de mar Marthasterias glacialis (Lamk.) en arrecifes del norte de Portugal

We examined whether the abundance and size of the starfish Marthasterias glacialis (Lamk.) exhibit a depthdependent partitioning on subtidal reefs. We tested the hypothesis that differences in food availability can result in habitat partitioning along a depth gradient. The abundance and size of M. glacialis was registered at 4 depth strata: 0-4 m, 4-8 m, 8-12 m, and > 12 m; we also recorded the number of food items that they were preying on. The abundance and size of M. glacialis decreased with depth. Mussels (Mytilus galloprivincialis) were the most preyed food item across all depth strata, followed by gastropods, sea urchins and barnacles; M. glacialis also consumed a significantly larger amount of mussels in feeding experiments compared with sea urchins and gastropods. The abundance of M. galloprivincialis beds decreased with depth. The clear link between the decrease in abundance and size of M. glacialis with depth and the decay of the most consumed prey (mussels) suggest that food availability may play an important role in the vertical distribution of this starfish, though wave-associated turbulence in the first few metres of the subtidal could also limit the abundance of M. glacialis.Examinamos si la abundancia y talla de la estrella de mar Marthasterias glacialis (Lamk.) exhibe una segregación batimétrica en arrecifes submareales. Contrastamos el modelo que predice que diferencias en la disponibilidad alimenticia puede resultar en una segregación del hábitat a lo largo de un gradiente batimétrico. La abundancia y talla de M. glacialis se registró sobre 4 estratos de profundidad: 0-4 m, 4-8 m, 8-12 m, y > 12 m; además registramos el número de presas sobre las que estaban depredando. La abundancia y talla de M. glacialis decreció con la profundidad. Los mejillones (Mytilus galloprivincialis) fueron la presa más consumida, seguido de gasterópodos, erizos de mar y cirrípedos; M. glacialis también consumió una cantidad significativamente superior de mejillones en experiencias alimentarias en relación a erizos de mar y gasterópodos. La clara asociación entre la caída en profundidad de la abundancia y talla de M. glacialis y la caída de su presa más consumida (mejillones) sugiere que la disponibilidad alimentaria juega probablemente un papel importante en la distribución vertical de esta estrella de mar. No obstante, individuos marcados mostraron un movimiento a corto plazo mayor sobre un estrato somero que sobre un estrato profundo, y por tanto, la turbulencia asociada al oleaje en los primeros metros del medio submareal también pudiera afectar el patrón ecológico de M. glacialis con la profundidad

Spatial patterns and response to wave exposure of shallow water algal assemblages across the Canarian Archipelago: a multiscaled approach

We conducted a mensurative survey to investigate spatial variability and the effect of wave exposure at a range of spatial scales including islands (100s of kilometres apart), locations within islands (10s of kilometres apart), and sites within locations (100s of meters apart), on the composition, abundance and distribution of shallow water algal assemblages across subtidal hard bottoms of the Canarian Archipelago (eastern Atlantic). A multi-scaled hierarchical sampling design provided the framework for quantifying the variation among samples due to each spatial scale and level of wave exposure. Haphazardly placed 50 x 50 cm quadrats were deployed in shallow rocky-reefs to assess community structure and dominance. Non-parametric multivariate techniques, as well as univariate tests, provided evidence to collectively suggest that shallow water algal assemblages differed between protected (leeward) and exposed (windward) shores, with a consistency of its effects across islands, while different spatial scales were also involved in the variability and patchiness of these assemblages. In this sense, differences were clearly taxon and/or group-specific. In general, the presence and abundance of frondose fucoid species was greater at exposed shores compared to protected shores, whereas turf-algae dominated protected shores at each island. Dissimilarities between islands for the overall algal assemblage generally increased with the distance between islands. In particular, the presence and abundance of fucoid species was larger in the eastern islands, while in contrast turf and bush-like algae increased in the western islands. The large-scale gradient of the oceanographic conditions in an east-to-west direction across the Canarian Archipelago provided a parsimonious explanation for this observation, yet some inconsistencies were observed in the overall regional pattern

Spatial patterns and response to wave exposure of shallow water algal assemblages across the Canarian Archipelago: A multi-scaled approach

We conducted a mensurative survey to investigate spatial variability and the effect of wave exposure at a range of spatial scales including islands (100s of kilometres apart), locations within islands (10s of kilometres apart), and sites within locations (100s of meters apart), on the composition, abundance and distribution of shallow water algal assemblages across subtidal hard bottoms of the Canarian Archipelago (eastern Atlantic). A multi-scaled hierarchical sampling design provided the framework for quantifying the variation among samples due to each spatial scale and level of wave exposure. Haphazardly placed 50 x 50 cm quadrats were deployed in shallow rocky-reefs to assess community structure and dominance. Non-parametric multivariate techniques, as well as univariate tests, provided evidence to collectively suggest that shallow water algal assemblages differed between protected (leeward) and exposed (windward) shores, with a consistency of its effects across islands, while different spatial scales were also involved in the variability and patchiness of these assemblages. In this sense, differences were clearly taxon and/or group-specific. In general, the presence and abundance of frondose fucoid species was greater at exposed shores compared to protected shores, whereas turf-algae dominated protected shores at each island. Dissimilarities between islands for the overall algal assemblage generally increased with the distance between islands. In particular, the presence and abundance of fucoid species was larger in the eastern islands, while in contrast turf and bush-like algae increased in the western islands. The large-scale gradient of the oceanographic conditions in an east-to-west direction across the Canarian Archipelago provided a parsimonious explanation for this observation, yet some inconsistencies were observed in the overall regional pattern

Marinas as habitats for nearshore fish assemblages: comparative analysis of underwater visual census, baited cameras and fish traps

Understanding the ecological role that artificial structures might play on nearshore fish assemblages requires the collection of accurate and reliable data through efficient sampling techniques. In this work, differences in the composition and structure of fish assemblages between the inner and outer sides of three marinas located in the temperate northern-eastern Atlantic Ocean were tested using three complementary sampling techniques: underwater visual censuses (UVC), baited cameras (BCs) and fish traps (FTs). UVCs and BCs recorded a comparable number and relative abundance of species, which in turn were much greater than those recorded by FTs. This finding supports the use of UVCs and BCs over FTs for broad ecologically studies, especially when dealing with structurally complex habitats such as artificial structures. We found differences in fish assemblage structure between the inner and outer sides of marinas, independently of the sampling method. Four small-sized species (Similiparma lurida, Thalassoma pavo, Sarpa salpa and Symphodus roissali) associated with structurally complex vegetated habitats dominated, in terms of abundance, the outer sides of marinas; Diplodus vulgaris, Diplodus sargus and Gobius niger, species with high ecological plasticity in habitat requirements, dominated the inner sides of marinas. The information provided in this study is of great interest for developing sound monitoring programmes to ascertain the effects of artificial structures on fish communities.info:eu-repo/semantics/publishedVersio

Divergencia genética de tanaidáceos (Crustacea: Peracarida) con baja capacidad de dispersión

In this study, the phylogeographic patterns of nuclear, ribosomal and mtDNA gene fragments of five tanaidacean species (Zeuxo, Tanaidae) from the Atlantic, Pacific and Mediterranean Sea were investigated. We aimed to interpret results in the framework of current hypotheses on the distribution of small invertebrates with very limited dispersal ability. Evidence for a surprisingly high genetic divergence was found for intertidal tanaidaceans from the North Atlantic. This is a result of poor dispersal potential, as tanaidaceans have direct development, no pelagic stage, and very limited swimming capacity. However, lower genetic divergence was found between an intertidal tanaid species from the North Atlantic and two from the North Pacific, which suggests a scenario of recent colonization following the last glacial maximum. The species Zeuxo normani was found to be a species complex consisting, at least, of Z. normani (California), Z. cf. normani (Japan), Z. cf. normani (Australia), Z. sp. A (Korea), and Z. holdichi (Spain and France). Our results showed that traditional species identification underestimates tanaidacean diversity and that what have been previously perceived as reliable diagnostic morphological characters, are, however, variable and unreliable.En este estudio, investigamos los patrones filogeográficos de fragmentos de ADN nuclear, ribosómico y mitocondrial de 5 especies de tanaidáceos (Zeuxo, Tanaidae) del Atlántico, Pacífico y Mediterráneo. Nos propusimos interpretar los resultados en el marco de hipótesis sobre la distribución de pequeños invertebrados con limitada capacidad de dispersión. Encontramos evidencia de una sorprendentemente alta diferenciación genética para tanaidáceos del medio intermareal del Atlántico Norte. Esto es resultado de una limitada capacidad de dispersión, ya que los tanaidáceos poseen desarrollo directo, carecen de estadíos pelágicos, y una limitada capacidad natatoria. Sin embargo, encontramos una baja diferenciación genética para una especie de tanaidáceo del Atlántico Norte y dos del Pacífico Norte, lo que sugiere un escenario de reciente colonización tras la última glaciación. La especie Zeuxo normani constituye un complejo de especies que, al menos, agrupa a Z. normani (Califonia), Z. cf. normani (Japón), Z. cf. normani (Australia), Z. sp. A (Corea) y Z. holdichi (España y Francia). Nuestros resultados mostraron que la forma tradicional de identificar tanaidáceos subestima su diversidad y que lo que previamente se consideraron como caracteres morfológicos claramente diferenciadores son, sin embargo, variables y poco fiables

Patrones espaciales en la estructura poblacional del caracol Stramonita haemastoma (Linnaeus, 1766) (Gastropoda: Muricidae) en el Archipiélago Canario (Atlántico oriental).

The goal of this study was to determine the consistency of the vertical distribution patterns of the predatory whelk, Stramonita haemastoma, in the rocky intertidal zone of the Canarian Archipelago (eastern Atlantic) across a hierarchy of five orders of magnitude of horizontal spatial variability (from tens of m to hundreds of km). In general, this species showed a consistent vertical zonation pattern across islands, with the majority of the specimens (74.65%) found in the mid intertidal zone. This result most likely reflects the whelk’s preference for a habitat with a large amount of potential prey but minimal stress induced by swells and desiccation. The mean abundance (0 to 1.73 ± 0.40 ind m-2, mean ± SE) and size structure (7 to 45 mm in shell length) of S. haemastoma in the Canarian Archipelago was considerably lower compared to those from continental areas in the Atlantic Ocean, which suggests that there are some differences between these populations. Natural mechanisms (e.g. isolation or poor recruitment events) and human perturbations (e.g. exploitation of intertidal resources) might influence the spatial distribution patterns.El objetivo de este estudio fue determinar la consistencia de los patrones de distribución vertical del caracol predador, Stramonita haemastoma, en el intermareal rocoso del archipiélago Canario (Atlántico oriental), a través de un modelo jerárquico que incluyó cinco órdenes de magnitud de variabilidad espacial horizontal (desde decenas de m hasta centenares de km). En general, esta especie mostró un patrón de zonación vertical consistente entre islas, con la mayoría de los ejemplares (74.65%) presentes en la zona intermareal media. Este resultado probablemente refleja una preferencia hacia un hábitat con mayor disponibilidad de presas, pero minimizando el estrés inducido por la exposición al oleaje y la desecación. El rango de abundancias (0 a 1.73 ind m-2, media ± SE) y la estructura de tallas (7-45 mm en longitud de concha) fueron notablemente bajos en relación a los observados en la costa continental del Atlántico, sugiriendo diferencias entre dichas poblaciones. Procesos naturales (e.g. aislamiento o eventos de escaso reclutamiento) y perturbaciones humanas (e.g. explotación de los recursos intermareales) pueden haber influido sobre estos patrones de distribución espacial

Rendimiento foto-fisiológico y aclimatación a corto plazo de dos macrófitos coexistentes (Cymodocea nodosa y Caulerpa prolifera) con la profundidad

Marine macrophytes are vertically distributed according to their ability to optimize their photosynthetic performance. We assessed the photo-physiological performance of the seagrass Cymodocea nodosa and the green seaweed Caulerpa prolifera at varying depth at Gran Canaria Island (Canary Islands, eastern Atlantic). The biomass of C. nodosa decreases with depth, while the opposite occurs for C. prolifera. Photochemical responses of both macrophytes were measured in shallow (5 m) and deep (20 m) waters at two times via chlorophyll a fluorescence and internal content of photoprotective pigments and antioxidant activity. We additionally carried out a reciprocal transplant experiment by relocating shallow and deep vegetative fragments of both macrophytes to assess their short-term photo-physiological acclimation. Overall, C. nodosa behaves as a ‘light-plant’, including a larger optimum quantum yield and ETRmax under scenarios of high photosynthetically active radiation and a larger antioxidant activity. In contrast, C. prolifera is a ‘shade-adapted’ plant, showing a larger carotene content, particularly in shallow water. Deep-water C. nodosa and C. prolifera are more photochemically efficient than in shallow water. The alga C. prolifera shows a rapid, short-term acclimation to altered light regimes in terms of photosynthetic efficiency. In conclusion, decreased light regimes favour the photosynthetic performance of the green alga when both species coexist.Los macrófitos marinos se distribuyen verticalmente de acuerdo a sus capacidades para optimizar su rendimiento fotosintético. Evaluamos el rendimiento foto-fisiológico de la fanerógama marina Cymodocea nodosa y el alga verde Caulerpa prolifera a diferentes profundidades en la isla de Gran Canaria (Islas Canarias, Atlántico oriental). La biomasa de C. nodosa decrece con la profundidad, mientras que para C. prolifera ocurre lo contrario. Las respuestas foto-químicas de ambos macrófitos se midieron en aguas someras (5 m) y profundas (20 m), en dos tiempos, a través de la fluorescencia de la clorofila a y los contenidos internos en pigmentos fotoprotectores y la actividad antioxidante. Además, ejecutamos un experimento de trasplante recíproco, recolocando fragmentos vegetativos de ambos macrófitos entre aguas someras y profundas para determinar su aclimatación a corto plazo. En general, C. nodosa se comporta como “planta de sol”, con mayor rendimiento cuántico óptimo y ETRmax bajo escenarios de alta radiación PAR y mayor actividad antioxidante. Contrariamente, C. prolifera es una “planta de sombra”, mostrando mayor cantidad de carotenos, en particular a poca profundidad. Ejemplares profundos de ambos macrófitos son más eficientes foto-químicamente que los de aguas someras. El alga C. prolifera muestra una aclimatación rápida, a corto plazo, de su eficiencia fotosintética ante cambios en el régimen luminoso. En conclusión, regímenes depauperados lumínicamente favorecen el rendimiento fotosintético del alga verde

Turban Snails as Habitat for Foliose Algae: Contrasting Geographical Patterns in Species Richness

Understanding patterns of species richness is a major goal for ecologists, especially in space-limited habitats where many organisms live on top of others (epibiosis, e.g. by algae growing on gastropods in marine environments). We tested the hypotheses that species richness of epiflora on the gastropod Turbo torquatus would not differ between regions with similarly rich algal floras, and that epifloral richness would increase with increasing gastropod size. Macroalgal floras of Hamelin Bay (HB), Marmion (M), Jurien Bay (JB) and Kalbarri (K), Western Australia, ranged from ~20 to 40 species reef–1 (JB = HB = M ≥ K). Epiflora on small T. torquatus (shell areacm2) did not differ among regions but epifloral richness increased with increasing basibiont size. Large T. torquatus (\u3e150 cm2) were only found in Hamelin Bay and Marmion, where epifloral richness differed substantially. Epifloral richness was positively related to basibiont size in Marmion but not in Hamelin Bay. However, densities of patellid limpets on large T. torquatus were ~4× higher in Hamelin Bay than in Marmion, implying that limpet grazing suppresses epifloral richness. Epifloral richness on turbinids is not simply associated with regional species pools or gastropod size; rather, biological interactions at the scale of individual basibionts apparently govern broad scale patterns of epibiosis